1. Field of the Invention
The present invention relates to a vehicular child safety seat placed on a seat of a vehicle and fastened to the seat of the vehicle using a seat belt with which the vehicle is equipped.
2. Description of the Background Art
In recent years safety measures have emerged as a critical factor for vehicles, and various vehicular child safety seats have been developed as a device for insuring the safety of a new-born baby, a baby, an infant, and a child of school age (referred to generically as "child" hereinafter) riding in a vehicle.
The Japanese Industrial Standard has established detailed standards in "Vehicle Equipment-Child Protection Device: JIS-D 0401-1996" with respect to a vehicular child safety seat.
According to the Japanese Industrial Standard, the type of a child protection device or child restraint is classified into "baby (including new-born baby) bed", "infant seat (for both forward and rear facing directions)" and "child seat". The classification is divided according to the weight range of the child, i.e., W1 (less than 10 kg), W2 (at least 9 kg and less than 18 kg), W3 (at least 15 kg and not more than 25 kg), and W4 (at least 22 kg and not more than 36 kg). In order to satisfy the safety requirements for the classes of W1 and W2, an infant seat, when used in a rear facing direction with respect to the direction of travel, must have a mechanism to prevent the tilted angle of the backrest, i.e. the angle of the surface of the backrest relative to the vertical plane, from exceeding the maximum of 60 degrees at the time of a crash accident on account of the rebound of the infant seat.
In general, the child protection apparatus for weight class W1 refers to an apparatus fixed to the seat of a vehicle in a direction lateral or facing rearward with respect to the direction of travel of a vehicle for babies aged 0-10 months. The child protection apparatus for weight class W2 refers to an apparatus fixed to a seat of a vehicle in a frontward or backward facing direction with respect to the direction of travel of the vehicle for infants from 6 months to 3 or 4 years (commercially available as a "child seat" in general). The child protection apparatus for weight class W3 refers to an apparatus for elevating the seat bottom plane for a child aged 3 or 4 years to 6 years (commercially available as a "booster" in general).
Various products have been developed as devices to be applied to vehicular child protection apparatuses for weight W1, W2 and W3.
The rate of usage of child protection apparatuses in vehicles in the Japanese society is extremely lower than that compared to US and European countries. The first factor can be ascribed to the lack of the parents in recognizing the danger associated with vehicles. Furthermore, if a child shows his/her reluctance in being seated in the child protection apparatus, there is a possibility that the child protection apparatus will not be used. These all come from the lack of danger appreciated by adults associated with vehicles.
In view of the foregoing, it is first necessary to reform the recognition of adults as to the danger associated with automobiles. Aggressive official activities by the government are expected. The problem of a child showing reluctance to use a child protection apparatus can be obviated more or less by always having a child seated in the child protection apparatus ever since his/her babyhood, i.e. before a baby begins to take notice, so that the child will take it for granted that a child protection apparatus must be used when riding in a car.
This is extremely important from the social point of view. Thus, a child protection apparatus that can be used consistently from babyhood to school age is desired in order to inculcate the habit and recognition of always using a child protection apparatus for children riding in a car. In other words, a child protection apparatus is desired that commonly corresponds to the specification of all the above-described weight classes W1 to W3.
However, child protection apparatuses currently available on the market are only solitary products for a respective single weight class W1, W2, or W3 independently, or a product that has a rotatable seat and a reclinable backrest as disclosed in Japanese Patent Laying-Open No. 1-113007. There is no product that can be commonly used for weight classes W1 and W2, or for weight classes W1 to W3. Although the vehicle infant restraint seat disclosed in the aforementioned Japanese Patent Laying-Open No. 1-113007 seems to be available for consistent usage for W1 and W2 in common, this seat apparatus is intended for only infants and children. It is not suitable for small babies and infants, particularly those in supine and prone positions. This is because the apparatus, when taking a bed-like flat position by reclining the backrest portion, has its head portion open with inadequate support for babies to be laid on the apparatus. This restraint seat does not have the requirements for weight class W1.